What is the product formed when nitrobenzene undergoes nitration?

Order of basic strength: $(A) Ph-NH_2$,$(B) Ph-NH-CH_3$,$(C) Ph-N(CH_3)_2$,$(D) \text{o-toluidine (2-methylaniline)}$

In the following reaction $X$ is
$CH_3NH_2 + X + KOH \to CH_3NC$ (highly offensive odour)

$A$ student has been given a compound $x$ of molecular formula $C_6H_7N$. $x$ is sparingly soluble in water. However, on addition of dilute mineral acid, $x$ becomes soluble in water. $x$ when treated with $CHCl_3$ and $KOH$ (alc.) produces $y$. $y$ has a specific unpleasant smell. On treatment with benzenesulphonyl chloride, $x$ gives a compound $z$ which is soluble in alkali. The number of different $H$ atoms present in $z$ is:

The increasing basicity order of the following compounds is:
$(1)$ $CH_3CH_2NH_2$
$(2)$ $(CH_3CH_2)_2NH$
$(3)$ $(CH_3)_3N$
$(4)$ $PhNHCH_3$

$A$ compound with molecular mass $180$ is acylated with $CH_3COCl$ to get a compound with molecular mass $390$. The number of amino groups present per molecule of the former compound is: